setup;
global h
h=0.5;

syms sim_x sim_y sim_u sim_f;
sim_u = 7*sim_x^7*sim_y^7+2*sim_x^3*sim_y^3+3*sim_x^9*sim_y^2+8*sim_x^6*sim_y^2;
sim_f = diff(sim_u,sim_x,2) + diff(sim_u,sim_y,2);

x = 2 : h : 14;
y = 3 : h : 16;

m = length(x);
n = length(y);

u = reshape(subs(subs(sim_u, x), y), m,n);
f = reshape(subs(subs(sim_f, x), y), m,n);

g=zeros(m,n);
g(1,:) = u(1,:);
g(:,1) = u(:,1);
g(m,:) = u(m,:);
g(:,n) = u(:,n);

%crop(f)
tic
v = solverPoi(crop(f), g, h);
toc
surf(abs(crop(u) - v));

abs(crop(u) - v)
